Plywood core machine



Nov. 22, 1949 o. s. BOLLING 2,488,759

PLYWOOD CORE MACHINE Filed Dec. 22, 1945 8 Sheets-Sheet 1 Nov. 22, 1949'0. S. BOLLING PLYWOOD CORE MACHINE Filed Dec. 22, 17945 8 Sheets-Sheet2 java/z i024 O. S. BOLLING PLYwooD CORE MACHINE Nov. 22, 1949 8Sheets-Sheet 3 Filed Dec, 22, 1945 no Sno bus s 8 Sheets-#Sheet 4 HIM O.S. BOLLING PLYwooD GORE MACHINE Nov. 22, 1949 Filed Deo.

Nov. 22, 1949 o. s. BOLLING 2,488,759

PLYWOOD CORE MACHINE Nov. 22, 1949 o. s. BOLLING *2,488,759

PLYWOOD CORE MACHINE Filed pee. 22, 1945 v 8 sheets-sheet e Nov. 22,1949 o. s. BoLLlNG PLYwooD CORE MACHINE a sheets-sheet '7 Filed Dec. 22,1945 Nov. 22, 1949 o. s. BoLLlNG 2,488,759

PLYWOOD CORE MACHINE Filed Dec. 22, 1945 8 Sheets-Sheet 8 l hva/220201m/4 df oZZZ/y Patented Nov. 22, 14949 PLYWOOD CORE MACHINE scar S.Bolling, Minneapolis, Minn., assigner to Meinen-Johnson Machine Company,Minneapolis, Minn., a corporation of Minnesota Application December 22,1945, Serial No. 637,085

,6 Claims.

My present invention provides an improved and highly efficient machinefor making sheets from relatively narrow strips, slats or blocks ofwood, or similar material.

Machines of the present invention are used primarily for gluing togetherwooden strips or slats to produce composite wood panels that aresuitable for various commercial uses, such as for plywood cores. In thisconnection, it will be understood that in the production of plywood, thecomposite panels or sheets produced by this machine will be securedbetween wooden veneer sheets by subsequent and additional operations andby use of additional machines or devices.

In the use of the improved machine of the present invention forproducing composite sheets from strip or slat material, slats or stripshaving glue applied to one edge of each strip (and before the glue isdried or set) are placed upon the receiving or input end of the machinein properly assembled relation and are fed from thence through a heatingzone while being maintained in tight edge-to-edge contact. The glue onthe previously edge-glued pieces thus becomes dried and set under heatand pressure while the material is subject to feeding movements throughthe machine, and a composite sheet is thus delivered from the output endof the machine.

In the machine of my present invention, as in the machine of my priorPatent 2,366,588, heating of the previously edge-glued and assembledslats or strips of work material to set and dry the glue is accomplishedby passing the said material between opposed heated plates and, as inthe case of the machine of my said prior patent, the edge-glued stripsof work material are maintained in tight edge-to-edge contact duringtheir passage through the space between the heating plates by resistanceto forward feeding action set up by squeezing pressure of the opposedhot plates on the material and by further resistance to forward feedingmovements of the material set up by a pressure-breaking mechanismlocated after the hot plates and adjacent the output end of the machine.The machine of the present invention, however, involves a number of veryimportant improvements over the machine of said prior patent, and whichinclude the following, to wit:

. a. The present invention provides an improved feeding mechanism forpositively feeding and continuously delivering work pieces (slats,strips, or the like) to and through the space between the opposed hotplates and the subsequent pressure mechanism.

b. The present invention further provides an improved hot platestructure involving spaced walls and intervening heating units. In thepreferred arrangement illustrated, the heating units are in the natureof steam-conducting heat lowing the hot plates.

transfer conduits running in zigzag fashion between opposite walls ofthe hot plates, and comprising relatively-straight laterally-spacedportions or sections extending between opposite longitudinal edgeportions of the hot plates and connected by elbows. In the preferredarrangement, the only joints in the heat transfer conduits are betweenthe relatively-straight portions or sections thereof and the connectingelbows. In accordance with the present invention, the said connectingelbows are located laterally outwardly of the marginal longitudinaledges of the hot plates, where they are readily accessible for thepurposes of inspection, repair of the joints between the elbows andstraight sections, and removal and replacement of the elbows orrelatively-straight conduit sections connected thereby.

c. Still another important feature of the present invention has to dowith the mounting of the feeding mechanism, hot plates, and the pressuremechanism following the hot plates, on, and the anchoring of the sameto, a supporting frame structure. It will be understood that the re- .Ysistance to feeding action of the material set up by the hot plates andthe pressure devices following the hot plates produces powerful forcestending to separate the feeding mechanism from the hot plates and thehot plates from the pressure mechanism following the same. l-Ieretofore,it has been the practice to anchor the several units independently tothe supporting frame structure to prevent longitudinal movements thereofwith respect to the frame and to one another, and in so doing thepowerful forces tending to separate the feedingmechanism from the hotplates and the hot plates from the pressure mechanism following the samewas absorbed entirely through the frame structure, with the result thatthe supporting frame structure was placed under powerful stresses andstrains tending to buckle and warp the same, and tending to producemisalignment between the feed mechanism, hot plates, and pressuremechanism fol- In accordance with the present invention, I overcome thistendency of prior art machines to buckle and warp the frame structure byconnecting the successive cooperating units comprising the feedmechanism, hot plates, and pressure mechanism following the hot plates,together in a tandem relationship, whereby the forces tending toseparate the said successive units of the machine are absorbed withinthe units themselves, and independently of the supporting framestructure. This important feature of the invention will be clarified andamplified later on in the specication and under the heading Operation d.The present invention further provides a novel and improved transmissionmechanism intermediate the prime mover or motor and the feed mechanism,whereby to permit free vertical movements of the upper unit of thesecondary feed mechanism with respect to the lower unit thereof whenboth are driven through common endless belts.

e. The present invention still further provides a novel automaticwork-actuated control mechanism for the work feeding mechanism, wherebythe feeding mechanism is automatically disrupted whenever the rate ofdelivery of work pieces to the secondary or positive feed portion of thefeed mechanism fails to equal the rate of feed of the said secondary orpositive feed portion of the feed mechanism. This feature is highlyimportant in that it prevents operation of the positive feed portion ofthe feed mechanism under conditions when the frictional contact areabetween said feed mechanism and the work is reduced to a point whereslippage will occur between the feed mechanism and work, and whichslippage, if allowed, would be apt to damage and deface the work.

f. The present invention still further provides an improved mechanismfor variably adjusting the pressure of the upper hot plate on the work.

The above and other highly important objects and advantages of thepresent invention will be made apparent from the followingspecification, claims, and appended drawings.

In the accompanying drawings, like characters indicate like partsthroughout the several views.

Referring to the drawings:

Fig. 1 is a front and side perspective view of a plywood core machineembodying the improvements of my invention;

Fig. 2 is a plan View of the machine of Fig. 1;

Fig. 3 is an enlarged longitudinal sectional view taken on the line 3 3of Fig. 2, and having,T some partsbroken away;

Fig. 4 is a fragmentary view in side elevation taken on the line 4 4 ofFig. 2;

Fig. 5 is a fragmentary view in elevation taken on the line 5 5 of Fig.2, and with some parts broken away;

Fig. 6 is a transverse sectional View taken on the line 6 5 of Fig. 5,and with some parts broken away;

Fig. 7 is a transverse sectional View taken on the line -I of Fig. 3,and with some parts broken away;

Fig. 8 is a fragmentary longitudinal sectional view taken on the line 88 of Fig. 2, with some parts being broken away and shown in section;

Fig. 9 is a fragmentary longitudinal sectional View taken on the line 99 of Fig. 7, with some parts broken away;

Fig. 10 is a greatly enlarged detail sectional view taken on the lineIii-II) of Fig. 3;

Fig. 11 is a detail sectional View on a greatly enlarged scale taken onthe line I I I I of Fig. 4;

Fig. l2 is a detail fragmentary sectional view taken on the line I2 I2of Fig. 2;

Fig. 13 is a fragmentary plan view taken on the line I3 3 of Fig. 5;

Fig. 14- is a fragmentary detail view, on an enlarged scale, taken onthe vertical line 4 I4 of Fig. 5,;

Fig. 15 is a fragmentary perspective view on an enlarged scaleillustrating the work pressure shoes and certain associated parts shownin side elevation in Fig. 5;

Fig. `15 is a fragmentary lView on an enlarged scale taken approximatelyon the line IB-IS of Fig. 9;

Fig. 17 is a fragmentary perspective view on an enlarged scale of one ofthe secondary feed chains; and

Fig. 18 is a diagrammatic View illustrating the electrical hook-up ofthe feed mechanism.

The supporting frame of the machine described is made up in threesections indicated by i, 2, and 3 respectively. The frame section I isat the input end of the machine and comprises laterally-spacedlongitudinally-extending beams 4 and supporting legs 5 and Il. The legs6 are rigidly tied together by cross-beams I and the inner ends of thebeams 4 are rigidly anchored to the said legs 6; the outer ends of thesaid beams 4 being rigidly tied together by a transverse tie-plate 8.The intermediate frame section 2 comprises a laterally-spaced pair of1ongitudinally-extending plates 9 extending between and rigidly tyingtogether the frame sections I and 3. The frame section 3, which extendsto the output end of the machine, comprises laterally-spacedlongitudinally-extending beams l@ and legs II and I2; the legs I2 beingconnected by transversely-extending beams I ly (see Fig. 5).

Mounted on the primary frame section I is a primary feed mechanismcomprising laterallyspaced endless link belts or chains I4. These linkbelts or chains I 4 run over wheels in the nature of pulleys I5 andwheels in the nature of sprockets I6. The several pulleys I5 are alljournalled on an idler shaft I'I that is mounted fast in frame beams 4.The several sprockets EG are all mounted fast on a shaft I8 that isjournalled in bearing flanges I9 that project one from each of severalinverted U-shaped chain guide rails 20. The chains I4 run over and aresupported by a table I4a rigidly secured to the frame beams li (seeFigs. l, 2, 3, and 9).

The primary feed chains I4 feed stock to a secondary stock-feedingmechanism compris` ing a laterally-spaced series of lower endless feedbelts or chains ZI and a laterally-spaced series of upper endless linkfeed belts or chains 22. At the input end of the secondary stockfeedingmechanism, the endless feed belts or chains 2 I run over wheels in thenature of pulleys 23, and the endless feed belts or chains 22 run oversimilar pulleys 24. The pulleys 23 are all iournalled on the shaft I8.The several pulleys 24 are each journalled on a different stub shaft andeach of the stub shafts 25 is individually mounted fast on a differentarm 26 of a floating frame structure immediately to be described. Thesaid "ioating frame structure comprises the said arms 2@ and a tie-bar21 (see Figs. 1, 2, and 3). The fioating frame arms 26, of which thereare several, extend in laterally-spaced parallel relation longitudinallyof the machine, and the said tie-bar 2l is bolted or otherwise rigidlysecured to the ends of said arms closest to the input end of the machine(see particularly Fig. 2). The other ends of said floating frame arms 25are journalled on a rotary shaft 2S (see particularly Figs. 2 and '7).The several endless feed belts or chains 22 run over the pulleys 24 andalso run over wheels in the nature of sprockets 25 that are mounted faston shaft 28. The shaft 28, as will be seen by reference particularly toFigs. 2, 3, 7, 8, and 9, besides being intermediately journalled in theend portionsof the several frame arms 26, are journalled adjacent theiropposite end portions in bearing bosses 30 of draw bars 3|. The shaft 28is anchored to the frame legs 6 by anchor links 3| that are pivotallymounted on said frame legs 6 at 3| and to radial flanges on the draw barhubs 38 at 38. The shaft 28, intermediate its ends, is furtherjournalled in bearing bosses 38 of additional draw bars 3|a (seeparticularly Fig. 2). The mounting of the other ends of the draw bars 3|and 3|a is important, and will be dealt with in detail later on. Thelower endless belts or chains 2| run over the said pulleys 23 andsprockets 32, that are mounted fast on a power-driven rotary shaft 33.The power-driven rotary Shaft 33 is journalled adjacent its oppositeends in bearings 34 on the supporting frame section plates 9 described(see particularly Fig. 7). Also, this power-driven shaft 33 isjournalled intermediate the bearings 34 in the free end portions ofrigidly-anchored draw arms 35, the importance of which will beemphasized later on.

The endless conveyor belts or chains I4, 2 I, and 22 are all driven froma suitable source of power, such as an electric motor 36, through powertransmission connections comprising a chain 31 running over a sprocket38 on the shaft of motor 36 and a speed-reducing sprocket 39 on atransverse shaft 48 journalled in suitable bearing brackets 4| on beamlIl (see particularly Figs. 3 and 4). A shaft 42 is journalled adjacentits ends in the frame plates 9 and is driven at reduced speed from theshaft 40 by a pair of endless link chains or belts 43 running oversprockets 44 fast on the shaft 48 and sprockets 45 fast on shaft 42.Shaft 33 is driven from the shaft 42 at reduced speed through pinions 46fast on the opposite end portions of shaft 42 that mesh with gears 41fast on opposite end portions of shaft 33 (see Figs. 4, 7, and 8). Theshaft 28 is driven from the shaft 42 through chains 48 (see Figs. 4 and7) running over sprockets 49 fast on opposite end portions of shaft 42,idler sprockets 58 journalled on a pair of stub shafts 5| that aremounted fast each on one of the plates 9, sprockets 52 mounted fast onopposite end portions of shaft 28, and yieldingly-biased pick-upsprockets 53. The pick-up sprockets 53 are idlers and. are journalled onthe free end portions of arms 54 that are pivoted at 55 to oppositeframe beams I8, and which are yieldingly-biased in directions to take upthe slack in chains `48 by adjustable tension springs 56 (seeparticularly Fig. 4.) The primary feed chains I4 are driven from shaft33 by a chain 51 running over a sprocket 58 fast on shaft 33 and aspeed-increasing sprocket 59 fast on shaft |8. It will be seen that theabove described transmission mechanism drives the chains 2| and 22 atlike speeds and drives the chains |4 at a somewhat increased speed withrespect to the chains 2| and 22. It will also be seen that thedifference in speed between pulleys 23 on 'shaft4 I8 and sprockets 59 onshaft I8 is compensated for by free rotation of the pulleys 23 on theshaft I8 (see Fig. 9).

The lower portions of chains 2| run through the inverted U-shaped guiderails 20 and the upper portions of said chains 2| are supported by andrun over the upper surfaces of said inverted U-shaped guide rails 20.The lower chainengaging portions of the chains 22 intermediate thepulleys 24 and sprockets 29 are yieldinglypressed downwardly byhold-down shoes 60 and coil lcompression springs 6| interposed betweeneach hold-down shoe 60 and a longitudinally extended pressure bar 62.The springs 6| are telescoped over small bosses on the hold-down shoes6l!` and corresponding bosses on the under surfaces of pressure bars 62.The pressure bars 62 each extend in closely-spaced parallel relation toa different floating frame arm 26, and these are held againstlongitudinal sliding movements by stop lugs 63 projecting from said arm26. The hold-down shoes 68' and pressure bars 62 are confined betweentheir respective cooperating floating frame arms 26 and retainer plates64 that are anchored to their respective cooperating floating frame arms26 by stud bolts 65 passed therethrough and threaded into bosses 66 onthe floating frame arms 26 (see particularly Figs. 3 and 10). The bosses66 adjacent the extreme ends of retainer plate 64 serve as stop lugs tolimit 1ongitudinal movements of the several hold-down shoes 60. Thepressure bars 62, which are yieldingly-pressed upwardly by coil springs6|, bear against a pair of upwardly-extended pressure legs 61 that arechanneled, as shown best in Fig. 10, to receive the upper portions ofthe bars 62. By reference particularly to Figs. 3, 7, and 10, it will beseen that the upwardly-extended pressure legs 61 are formed withtransversely-extended passages 68 to receive the upper portions of linkbelts or chains 22. The pressure legs 61 are connected to the undersurfaces of a pair of transversely-extended bridge beams 69 byscrew-threaded pressure-adjusting studs 10. These pressure studs 1l] areprovided with diametrically-reduced upper end portions that work looselythrough apertures in the lower flanges of the bridge beams 69, and areprovided near the lower extremities of said diametrically-reducedportions with stop shoulders 1| that engage the under surfaces of saidbeams 69 and limit upward movements of the studs 10 therethrough. Thescrew-threaded lower portions of the studs 18 are screw-threadeddirectly into the pressure legs 61, as shown best in Figs. 3, 7, and 10,and are locked in adjusted positions by lock nuts 12. The bridge beams69 are vertically adjustably supported from the frame legs 6 (see Figs.4, '1, and 8) by upstanding screw-threaded shanks 13 on legs 6,nut-acting worm gears 14 screw-threaded on the Shanks 13, and gear boxes15. The upper ends of the shanks 13 work loosely through the lowerflanges of the beams 69, and the nutacting worm gears 14 are journalledwithin the gear boxes 15. The nut-acting worm gears 14 are operatedexternally of the gear boxes 15 by operating mechanism comprising adriven shaft 16 within the gear box and journalled in the end portionsthereof, worms 11 on the shafts 16 and meshing with the worm teeth ofthe nut-acting worm gears 14, bevel gears 18 fast on shafts 16, andintermeshing bevel gears 19 on an operating shaft 8|ll that isjournalled in bearing flanges 8| (see Figs. 1, 2, 7, and 8) and isequipped with an operating wheel 82. From the above, it will be clearthat the amount of yielding pressure exerted on the work, indicated byY, through the lower runs of the chains 22, springs 6|, pressure bars62, and pressure legs 61, may be adjustably varied by rotation of thehand wheel 82. Before going further, it is desirable to call attentionto the fact that the work Y is in the nature of a plurality of stripsextended transversely of the machine and brought into edge-to-edgecontact, and that the receiving end portion of the floating conveyor orfeed unit comprising pulleys 24,

sprockets 29, andA chains 22is limited against 7 downward movements'byhanger bolts v83 that are threaded into and project upwardly 'from ythefloating frame arms 26 Yand Work loosely through brackets 84 projectingfrom beams 80 (see Figs. l and 3). Downward movements of the floatingupper conveyor unit comprising-chainsZZ are adjustably limited by nuts85 on the upper ends of `hanger'bolts 83, and which normally are spacedabove the brackets 81%. The object of these nutequipped hanger bolts v83is to maintain a predetermined spacing less than the thickness of thework between the cooperating lower and upper chains 2| and 2-2respectively in the absence of work strips Y therebetween, so thatstrips Y may be readily fed into the space therebetween. It is alsodesirable to call attention tothe fact that the feed chains Z'I and 22are provided on their work-engaging faces with gripping teeth, as shownbest in Fig. 1'7, which is a perspective View respective of both of thechains 2| and chains 22. The secondary feed mechanism comprising thechains 2| and 22 feeds strips of work material Y between upper and lowerhot plates 86 and 81 respectively. These hot plates 86 and 81, as shown,are made up of three similar sections rigidly connected together as at88 (see Figs. 2, 3, and 12), Each sectionof each of the hot plates 8Band 81 comprises a flat metallic work-engaging wall 89, a backing wall90, and an intervening heating element 9|. of each section of each ofthe hot plates 86 and 81' is in the nature of a `heat transfer conduitcomprising laterally-spaced parallel portions extending transversely ofthe hot plates and connecting elbows 92 that are located laterally outy,

wardly of the marginal edges of the walls 89 and 98 of their respectivehot plate sections (see Figs. 2 and 16) Preferably, the laterally-spaced'paralle] sections and connecting elbows of the heat transfer conduits9| are formed of cross-sectionally square seamless tubing providingmaximum heat transfer efciency between the conduits and work-engagingheat transfer plates 89. Preferably, also, the elbows 92, shown best inFig. 16, are welded or brazed to the ends of the straight sections ofthe conduits 9| at points outwardly of the marginal edges of the hotplates, where the joints are readily accessible at all times forinspection and repair. Preferably, the otherwise exposed elbows 9-2` arecovered by guard channels 934 suspended by brackets 94 (see Fig. 11).The work-engaging heat transfer plate 89 and the backing plate 90 ofeach hot plate section are rigidly, but detachably, connected togetherby stud bolts 95 passing through the walls 90 and screw-threaded intobosses 08 projecting from the walls 89 (see Fig. 12).

The lower hot plate 81 is slidably seated 'on transverse cross members91 on longitudinal frame beams I0 through the medium of shoes 98v rigidon the backing walls 9| of the lower hot plate. Lower hot plate 81 isanchored Vat its receiving end 'to the sprocket shaft 33 by means of thebefore-mentioned draw arms 35, which draw arms are journalled on theshaft 33 and rigidly anchored t'o the work-engaging Wall 8'0 'of thelower hot plate by cap 'screws or the like 89 threaded into bosses |80projecting from and rigid with-the wallY 89 4(see Figs. 3, 8, and 9) Thelower draw arms 35 are equal in number to, and located directly below,the draw arms 3| and 3| a of the upper hot plate 86.

'I-he upper hot plate 88- normally rides on and is maintained underpressure against the work str-ipsV Y in a manner hereinafter described,but L The heating element 8 is held against bodily movementslongitudinally cf the'machine'by the before-described draw links or bars3| and 31a, which are pivotally anchored at their outer ends to theshaft 28, and which are pivotally anchored to the work-engaging wall 89of the upper hot plate 86 at |0| through the medium of upstandinganchoring flanges or brackets |02 that are bolted or otherwise made fastto the wall 89 by cap screws or the like |03. Of course, it will beclear that the links or bars 3| and 3|a, being pivoted at both ends,permit free vertical movements of the upper hot plate 86.

Mounted on the upper hot plate 85 is a superstructure comprising alaterally-spaced pair of longitudinally-extended beams |04 that areclamped to a plurality of underlying transverse beams |05 vby clampinggibs |06, shown best in Fig. 11, whereby to permit free movements of thebeams |05 with respect to the beams |04 as a result of expansion andcontraction of the upper hot plate 86, to which the said beams |05 areanchored in a manner immediately to be described. With referenceparticularly to Fig. 11, it will be-seen that the beams |05 are providedwith legs |01 having outturned feet |08, and it will be further seenthat springs |09 are interposed between the feet |08 and the upper hotplate, whereby to transfer the Weight of the superstructure to the upperhot [plate 86. The superstructure is positively anchored to the upperhot plate by nut-equipped bolts ||0 screw-threaded into transverse ribsI of the upper hot plate 85 and passed upwardly through the springs |00and feet |08 with the nuts thereof applied above said feet |08. At thispoint, attention is incidentally called to the fact that the supportingbrackets 94 of the projecting channels 93 are anchored `directly to thelegs |01, as shown best at H12 in Fig. 11. The transverse ribs may beassumed to be welded or brazed directly to the work-engaging heattransfer wall 89 of the upper hot plate 86.

The weight of the above-described superstructure will provide a minimumoperating pressure on the upper hot plate 86, but for producingadditional pressure and for raising the upper hot plate and itssuperstructure, I provide a pressure-adjusting and lifting mechanismimmediately lto be described, This adjusting and lifting mechanismcomprises a pair of transversely-extended shafts H53 located adjacentopposite ends of thevsuperstructure ybeams |04 and over opposite end`por-tions of the upper hot plate 86. These shafts H3 are eachjournalled at one end in a bearing block H4 carried by the under surfacecfone of the beams |04: (see Fig. 3) and at its other vend each of saidshafts H3 is journalled in a gear caseV i i5 carried by and secured tothe under surface of an opposite beam |04. At their extreme outerrends,the shafts ||3 are provided with cranks y| i6 that may be assumed to bekeyed thereto for common `rotation therewith. The several cranks |18Vare connected by rigid links ||1 to frame beams i0 at their respectivesides of 'the machine. The links ||1 are pivotally connect-ed to theirrespective cranks ||6 at ||8 and are pivotally connected at their lowerends to bearing rackets H9 that are vertically adl'ustably anchored tothe frame beams |8 through the medium of anchoring brackets |20 andnut-equipped bolts :521. For operating the several cranks ||6 and their'respective shafts ||3 in unison and from aicommon operating point, Iprovide an operasing Emechanism comprising worm gears |22, cooper-'atingworms i 2 3, a lo'ngitudinally-extended operating shaft |24, a ratchetgear |25 fast on shaft |24, an operating lever |26 having a bifurcatedend` journalled on the shaft |24, and a reversible ratchet |21 (seeFigs. 2, 5, and 14) The worm gears |22 are mounted fast on their re.-spective shafts ||3 each within a different gear case H5, and the worms|23 are mounted fast on shaft |24 each within one of the gear cases andmeshing with a cooperating worm gear |22. The reversible ratchetmechanism described is of well-known Iconstruction, not requiringfurther description, particularly in view of the fact that a hand wheelor other operating means could be substituted therefor for operating theshaft |24 in two directions. It will, however, be understood thatoperation of the shaft |24 in one direction will result in lifting ofthe upper hot plate 86 free of the work strips Y and that operationthereof in the other direction will place the rigid links |1 undertension to lcompress the several springs |89 to adjustably increase thepressure exerted on the upper hot plate 86 and by said plate 85.011. theinterposed work strips Y.

Before going further, it is desired to call attention to the fact thatsuitable heating medium, preferably steam, is introduced at the inputend portions of the upper and lower hot plates 85 and 81 respectively bysteam pipes 85' and 81 respectively, and which are respectivelyconnected to the ends of heat transfer conduits 9| of the I upper andlower hot plates (see Fig. 4). Also, by reference particularly to Fig.5, it will be seen that the steam is returned to the source or exhaustedto atmosphere, as desired, through conduits 85 and 81 leading from theopposite ends of the heat transfer conduits 9| of the upper and lowerhot plates respectively, and which are located at the output ends ofsaid conduits. Now, by particular reference to Figs. 2 and 5, it will beseen that the sections of the heat transfer conduits 9| serving adjacentsections of the upper and lower hot plates 85 and 81 are connected inseries by connecting elbows |28.

For the purpose of guiding the work strips Y into the space between theupper and lower hot plates 86 and 81, and which space will be somewhatless than the thickness 'of the work strips Y when the said space isfree of work strips, I provide at the input ends of the hot platesoutwardly and forwardly-extending cam shoes |29. There are several ofthese cam shoes |29 rigidly secured to and projecting forwardly from theinput edge of each of the hot plates 85 and 81 (see Figs. 9 and 16particularly), and which operate as upper and lower pairs; eachcooperating upper and lower pair of cam shoes |29 being provided with areversely-flared cam-acting end, whereby to receive the work strips Yand guide the same into the space between the upper and lower hotplates. The cam shoes |29 further act to prevent the work strips Y frombuckling in the space between the output end of the secondary feedmechanism and the hot plates, particularly when the work strips are verynarrow in width.

In machines of this character, it is highly desirable that theedge-glued work strips Y be maintained under relatively very greatedgewise squeezing pressure during their passage through the hot plates8S and 81, and, therefore, for further increasing the edgewise squeezingpressure on the work strips as they pass through the hot plates, Iprovide adjacent the output end of the machine and beyond the hot plates36 and 81 a friction-retarding mechanism comprisingl l shortlongitudinally-extended skid rails |38 below the work strips Y andcooperating pressure shoes |3| above the moving work strips Y, whichlatter will, by the time they reach the output end of the machine, beunited into a unitary sheet. There are a laterally-spaced series of thelongitudinally-extending skid rails |38 that are rigidly anchored to andproject from the output end of the lower hot plate 81, and these extendover and rest upon transverse beams I3, and on which beams the skidrails |30 are free for longitudinal sliding movements as a result ofexpansion and contraction of the lower hot plate. Pressure shoes |3|, ofwhich there are a laterally-spaced series, are anchored to the outputend portion of the upper hot plate .86 by leaf springs |32 (seeparticularly Figs. 5 and 15). By reference particularly to Fig. 15, itwill be seen that the leaf springs |32 are each'connected at one end tothe intermediate portion of a pressure shoe |3| and are each rigidlyconnected at the opposite end thereof by a bolt |34 and a key |35 to atransverse rib |33 that is mounted fast on the heat transfer wall 89 ofthe upper hot plate 86.

For the purposes of lifting the pressure shoes i3! out of engagementwith the Work and out of the path of travel of the work, and forapplying varying degrees of downward pressure thereon, I provide amechanism comprising transverse beams |35 and pressure rods |31. Thetransverse beams |36 are connected at their bottoms by a plate |38, andare vertically adjustably supported from legs I2 through the medium ofscrewthreaded studs |39 and nut-acting worm gears |48. Thescrew-threaded studs |39 have reduced diameter portions extended throughthe upper ends of the legs l2 and clamped thereto by nuts Mi. Thenut-acting worm gears |48 are threaded on the studs |39 within gearboxes |43 attached to the under surfaces of opposite end portions ofbeams |35. By reference particularly to Fig. 5, it will be seen that thenut-acting worm gears |49 are provided with bearing hubs journalled inopposite walls of the gear boxes |43. The nut-acting worm gears |40 areall operated in unison from a hand wheel |44 through driving connectionscomprising a long transverse shaft |45 journalled in bearing bosses orbrackets |46 projecting from opposite gear boxes |43, bevel gears |41mounted fast on shaft |45, cooperating bevel gears |48 fast on shafts|49, and worm gears |58. The shafts |48 are each journalled at oppositeend portions in an opposite gear box |43 and the worm gears |58 aremounted fast on their respective shafts |49 and mesh each with adifferent Worm gear |48 (see Figs. 2, 5 and 6). The pressure rods |31are anchored fast at their lower ends each to a dif- .ferent pressureshoe |3| and all project upwardly through the beam-carried plate |38(see Fig. 5). The pressure rods |31 work loosely through the plate |38and are provided below the'plate |38 each with a `compression spring|5|. The springs i5! are compressed between the plate |38 and nuts |52on said rods. For the purpose of limiting relative downward movements ofthe pressure rods |31 through the plate |38, suitable stop nuts or thelike |53 are provided on the upper end portions of said rods |31. Fromthe above, it will be clear that the amount of pressure exerted by thepressure shoes |3| on the work may be adjustably varied at will bymanipulation of the hand wheel |44, which may also be manipulated toelevate the pressure shoes |3| out of the path of travel cf the work, ifand when da sired. Also, it should be noted that the frictional pull ofthe work on the pressure shoes ISI is transmitted to the upper hot;plate in a substantially straight line throughthcir respective anchoringleaf springs |32, which relieve the pressure rods |31 entirely of strainin a horizontal direction.

In practice, it has been found` that if the feed chains 2| and 22 bepermitted to operate faster than material is being delivered to thechains I4 and by the chains |4` to said chains 2| and 22, the chains 2|and 22 will start slipping on the Work after the last work piece Y hasadvanced to some indefinite point intermediate the ends of the chains 2|and 22 depending upon the amount of pressure applied to the work by thehot plates 86 and 81 and hold down shoes I3I. Such slippage between thechains 2| and 22 and the work pieces Y is, of course, objectionablebecause such slippingis apt to deface the work. It will be noted,however, that slippage occurring between the primary feed chains |4 andthe work strips Y, becauseV of the greater speed of travel of said feedchains I4, is permissible because of the relatively smoothupper'surfaces of said feed chains I4 and relatively light weight ofsaid work strips Y. To prevent such damaging slippage between the chains2| and 22 and the work, it is highly important that work strips Y be fedby the chains I4 to the. space between the cooperating chains 2| and 22at a rate equal to or faster than the rate of delivery by the chains 2|and 22, so as to maintain a maximum area of frictional driving contactbetween the chains 2| and 22 and the work during-all operating periodsof saidchains 2| and 22. To this end, I provide a pair of worklstripoperated switches |54 above the chains I4 and ahead of the chains2| and 22. These switches |54 are mounted on the transverse tie-bar 21,and each comprises a casing |55, a work-engaging arm |56 pivoted to itsrespective housing |55, a pair of fixed contacts |51, and' a bridgecontact |58 carried by the free end ofv an arm |59 that isrigidlyanchored to the pivoted end of its cooperating lever or arm |56.The arms |56and |59 form bell cranks andmay be assumed to be gravityactuated-toward switch-open positions. By-reference particularly toFgs.9 and 18, it will be seen that the free ends of the bellcrank arms-I53-nor mally ride on the upper surface of the work'strips beingffed tothe space between thechains |2I and |22-, and by reference to Fig. 18,it will be seen that the work strips Y keep the bell cranks inswitchclosed positions, and by reference to Fig. 18, it should beobvious that when' there is an absence of work strips Y under thefreeends of the bell crank arms |56, that the said bell cranks will be movedby gravity to switch-openpositions, not shown. The switches |54 operatein conjunction with a relay'switch |66 to automatically controloperation of the feed mechanism driving motor 36 in the followingmanner: By reference now to the diagram of Fig. 18, it will be seen thatthe motor 36 is operated from a threephase power line |6| through leads|62, |63, andV |64, which respectively have interposed thereinspacednxed switch contacts |62', |63', and |64 of the relay switch |66.The said relay switch |66 further comprises asolenoid winding |66 and asolenoid plunger |61 Carrying bridge contacts |62", |63, and 64 forcoopera-tionY respectively with pairs of spaced contacts |62', |63?, and|64'. The saidY relay switch |66.. also embodies-a pair of fixed switchcontacts |68` and a cooperating plunger-carried2 bridge contact,- |69,Therelay switch |66vis of the type that is yieldingly biased by gravityor otherwise toward open position, and from an examination of Fig. 18,it will be clear that when the relay switchV |66 is closed byenergization of the solenoid coil |66 thereof that the leads |62, |63,and |64 to the motor 36 will be completed and the motor renderedoperative. The solenoid coil |66 of the relay switch is initiallyenergized to close switch |60 by a starting circuit comprising aY lead|16 extending from a point in lead |63 ahead of switch |66, a short lead|16, a manually-closed self -opening starting switch |1|, a lead |12,coil |66, and a lead |13 extending to lead |64. Momentary closing of theabove-described starting circuit results in closing of all of thecontacts of relay switch |66, thereby rendering the motor 36 operativeand establishing a holding circuit for the solenoid coil |66; thelatter, however, being dependent upon closing of the switches |54 bywork pieces Y. This holding circuit comprises lead |16, a manually openself-closing switch |14, a lead |15, switches |54, a lead |16, nowclosed contacts |68and |69 of relay |66, a lead |11, part of lead |12,relay coil |66, and lead |13. The manually open self-closing switch |14is used to break the holding circuit and render the relay switch |66 andmotor 36 inoperative independently of Work strip-operated switches |54.

Operation Preparatory to feeding strips of work material Y to the upperand lower hot plates 86 and 81, steam or other suitable heating mediumwill be passed through the heat transfer conduits 9| of the hot platesfor suiiicient time to bring the said hot plates up to the desiredtemperature. Before starting the feeding mechanism com-- prising feedchains |4, 2|, and 22, a plurality of work pieces Y will be assembled onthe now stationary feed chains 4 of the primary feed mechanism, and thisprimarily-assembled unit of work pieces will be pushed forwardly overthe feed chains I4 under the work-actuated switches |54, thereby closingsaid switches |54. The machine is now ready for operation and the feedmechanism thereof will be set in motion by momentarily closing themanually-closed, selfopening switch |1|, which may be assumed to beconveniently located on the machine. (For a detailed description of thehook-up of the e1ectric motor 36, switches |54, relay switch |66, andswitches 1| and |14, see the foregoing part of the specification.) Withthe feed chains I4, 2|, and 22 now in operation, the work strips Y,manually placed upon the primary chains I4, will be fed to the spacebetween lower and upper chains 2| and 22 respectively, and will bepositively fed by the upper and lower secondary feed chains 2| and 22 toand through the space between the hot plates 86 and 81 and into andthrough the spaces between the final pressure mechanism comprising theskid rails |36 and the cooperating pressure shoes |3|. It will, ofcourse, be understood that work strips Y will be continuously placedupon the primary feed chains I4 for continuous delivery to the feedchains 2| and 22. In this connection, it is important to bear in mindthat the primary feed chains I4 are driven at a somewhat greater speedthan are the feed chains 2| and 22 of the secondary feed mechanism, soas to produce a continuous, although not great, slippage between thechains E4 and.y the work strips, which will maintain the work strips orpieces' Y in compact edgetoedge contact for delivery tothe feed chains2| and 22.

13 It will, of course, be understood, that the work strips or piecesplaced upon the primary feed chains i4 will have had glue or otherheatdrying adhesive previously applied to the edges thereof. As theedge-glued strips or work pieces Y are passed between the upper andlower hot plates 8S and 8i respectively, they will be subject to arelatively high temperature for a sufficient period of time tocompletely set and dry the glue while they are being maintained underedgewise crowding pressure one against the other as a result of thefrictional resistance to forward feeding movements of the work set up bypressure exerted on the work by the hot plates themselves and by furtherresistance to feeding movements set up by the final pressure mechanismcomprising the skids its and the cooperating shoes |35. The work strips,thus being united while passing between the hot plates, are deliveredfrom the pressure shoes I3! at the output end of the machine in acontinuous sheet which will be cut into desired lengths by a subsequentmachine. As previously indicated in the body of the specification, thepressure exerted by the pressure shoes I3! and the hot plates B6 and 3lon the work may be adjusted, through mechanism described, to place thework Y under the desired edgewise pressure during its passage betweenthe hot plates, and the pressure exerted by the chains 2l and 22 on thework may be adjusted, in the manner described, to obtain sufficientdriving traction to positively overcome the resistance to feedingmovements set up by the hot plates and the nal feeding mechanisminvolving skid rails |341 and pressure shoes IBI. f

As indicated in the introduction, a very important phase of the presentinvention is the manner in which the secondary or positive feed portionof the feed mechanism, upper and lower hot plates, and the pressuremechanism tt-13E, are mounted and anchored. In this connection,attention is directed to the fact that the lower unit of the secondarypositive feed mechanism, and which comprises chains 2l, pulleys 23, andsprockets 32, is anchored directly to the supporting frame structurethrough the medium of shafts i8 and 33 and flanges i9 on U-shapedmembers 253 and the intermediate frame side plates 9 respectively. Theupper unit of the secondary or positive feed portion of the feedmechanism, and which comprises feed chains 22, pulleys 2e, and sprockets29, is free for vertical movements and normally rests upon the surfaceof the work, but is anchored against longitudinal ymovements withrespect to the supporting frame by the rigid links 3 I With these factsin mind, attention is again directed to the fact that the lower hotplate 8l is free floating on the underlying,r frame structure and isconnected at its input end portion to the shaft 33 of the secondary feedmechanism through the draw arms 35, so that the forces tending to pushthe lower hot plate 8l longitudinally with respect to the drivingmechanism are transmitted directly to. the delivery end portion of thefeed mechanism through a tandem, substantially straight line connectionthrough draw bars 35 independently of the supporting frame structure. Ina like manner, the upper hot plate 86, which floats`v upon the work, isconnected in tandem to the output end portion of the upper unit of thesecondary feed mechanism comprising chains 22 through draw bars 3! andSla that connect directly to the shaft 28. Hence, the tendency of theupper hot plate to be moved longitudinally 14 of the machine and withrespect to the chains 22, is absorbed through the draw bars 3l and 3|aindependently of yand without placing k any stresses or strains upon thesupporting structure. As we go to the output end of the machine, we notethat the final pressure mechanism comprising the skid rails I3@ and thepressure shoes I3! also is anchored indirectly to the positive feedmechanism by being connected to the delivery end of the hot plates,whereby the tendency of the rails i! and shoes ISI to be movedlongitudinally of the machine by frictional engagement with the work istransmitted back to the source of pressure independently of the framestructure and without producing any strains or stresses thereon. Inother words, with the arrangement illustrated, a frictional vload of thework on the pressure plates and final pressure mechanism respectively istaken through straight line connections to the source of driving energyindependently of the frame structure and without any tendency to warp orbuckle the same. Obviously, this important feature permits the use oflighter framing and substantially eliminates any likelihood of thesuccessive cooperating elements of the machine being thrown out ofproper working alignment.

It will be noted by reference to Fig. l0 that the hold down shoes Si)are provided with laterallyextended flanges 60' that are containedwithin guide recesses 25' and 64 Aof the oating frame arms 26 and theretainer plates Ei respectively, to prevent the shoes 60 from beingpushed by the springs -Bl out of engagement with the arms 26 andretainer plates 64, in the absence of work strips Y under the `chain 22.

The commercial form of the machine has been illustrated and described,but it will be understood that various modifications as to details ofconstruction, combinations and arrangement of parts, may be made withinthe spirit of the invention herein disclosed and claimed.

What I claim is:

l. VIn a machine of the kind described, a supporting frame structure,spaced hot plates supported on said frame and adapted to have workpieces passed therebetween, feeding mechanism mounted on said frameahead of the hot plates and arranged to feed edge-glued strips inedge-toedge contact through the space between the hot plates, meansbiasing the hot plates toward one another to resist feeding movements ofthe work and thereby cause work pieces to be forced into tightedge-to-edge contact during their passage between the hot plates, meansanchoring the feeding mechanism to the frame structure and againstmovements longitudinally of the machine, and n leans anchoring thereceiving end portions of the hot plates directly to the output endportion of the feedA mechanism independently of the frame, said hotplates being not otherwise anchored against movements longitudinally ofthe machine, whereby the forces frictionally transmitted by the workfrom the feed mechanism to the hot plates will be transmitted from thehot plates directly back to the feed mechanism independently of thesupporting frame structure and without'setting up stresses in the lattertending to warp the same.

2. The structure defined in claim 1 in which the means anchoring thereceiving end portion of one of the hot plates directly to the outputend portion of the feed mechanism comprises a drawbar pivotallyconnected at one end to the receiving end portion of said hot plate andat its other end to the output end portion of the feed mechanism.

3. In a machine of the kind described, a supporting frame structure,spaced lower and upper hot plates supported on said frame structure andadapted to have work pieces passed therebetween, feeding mechanismmounted on said frame structure ahead of the hot plates and adapted tofeed edge-glued work pieces in edge-to-edge contact through the spacebetween the hot plates, said feeding mechanism comprising lower andupper endless belts adapted to frictionally engage the lower and uppersurfaces respectively of the work, the lower of said feed belts runningover wheels journalled in the supporting frame structure, the upper ofsaid endless belts running over wheels that are journalled in a floatingframe structure that is vertically movable with respect to thesupporting frame structure, means biasing the hot plates toward oneanother to resist feeding movements of the work and thereby cause thework pieces to be forced into tight edge-to-edge contact during theirpassage between the hot plates and as a result of feeding pressureexerted thereon by the feed mechanism ahead of the hot plates, meansanchoring the receiving end of the lower hot plate to the supportingframe structure adjacent the receiving end of said hot plate and thedelivery end portion of the lower endless feed belt, a substantiallyhorizontally-disposed draw arm pivotally connected to the receiving endportion of the upper hot plate at one end and at its other end beingjournalled on the shaft carrying the upper feed belt wheel adjacent theoutput end of the feed mechanism, and a substantiallyhorizontally-disposed link pivotally connected to the supporting framestructure at one end and to said draw bar at its other end, said lowerand upper hot plates being not otherwise anchored against movementslongitudinally of the machine.

4. The structure defined in claim 3 in which the said anchoring meansfor the lower hot plate is in the nature of a draw bar anchored at oneend to the receiving end portion of the lower hot plate and journalledat its other end on the shaft carrying the wheel for the lower endlessfeed belt that is located adjacent the output end of the feed mechanism.

5. The structure defined in claim 3 in further combination with pressuremechanism adjacent the output end ofthe hot plates involving spacedlower and upper friction elements adapted to engage the lower and uppersurfaces respectively of the work after the work has passed the hotplates and further resists feeding movements of the work, whereby tofurther increase the edgewise pressure of the work pieces one againstthe other during their passage between the hot plates, the lower of saidfriction elements being secured directly to and extending from thedelivery end portion of the lower hot plate, a resilient arm anchored toand extending from the upper of said friction elements and connected tothe output end of the upper hot plate, and yielding means biasing thevsaid upper friction element toward the lower friction element, wherebythe forces frictionally transmitted by the work from the feed mechanismto the hot plates will be transmitted from the hot plates directly backto the feed mechanism 116 independently of the supporting framestructure and without setting up stresses in the latter tending to warpthe same.

6. In a machine of the kind described, a supporting frame structure,spaced hot plates supported on said frame and adapted to have workpieces passed therebetween, feeding mechanism mounted on said frameahead of the hot plates and arranged to feed edge-glued strips inedge-toedge contact through the space between the hot plates, meansbiasing the hot plates toward one another to resist feeding movements ofthe work and thereby cause work pieces to be forced into tightedge-to-edge contact during their passage between the hot plates, meansanchoring the feeding mechanism to the frame structure and againstmovements longitudinally of the machine, means anchoring the receivingend portions of the hot plates directly to the output end portion of thefeed mechanism independently of the frame, said hot plates being nototherwise anchored against movements longitudinally of the machine,whereby the forces frictionally transmitted by the work from the feedmechanism to the hot plates will be transmitted from the hot platesdirectly back to the feed mechanism independently of the supportingframe structure and without setting up stresses in the latter tending towarp the same, pressure mechanism adjacent the output ends of the hotplates involving spaced lower and upper friction elements adapted toengage the lower and upper surfaces respectively of the work after thework has passed the hot plates and further resists feeding movements ofthe work, whereby to further increase the edgewise pressure of the workpieces one against the other during their passage between the hotplates, the lower of said friction elements being secured directly toand extending from the 'delivery endy portion of the lower hot plate, aresilient arm anchored to and extending from the upper of said frictionelements and connected to the output end of the upper hot plate, andyielding means biasing the said upper friction element toward the lowerfriction element.

OSCAR S. BOLLING.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 273,723 Goff Mar. 13, 1883828,069 Steger Aug. 7, 1906 915,504 Sutter Mar. 16, 1909 1,693,606 JonesDec. 4, 1923 1,702,185 Weber Feb. 12, 1929 1,859,370 King May 24, 19322,108,920 Humiston Feb. 22, 1938 2,305,525 Gustin Dec. 15, 19422,366,588 Bolling Jan. 2, 1945 2,398,353 Bolling Apr. 16, 1946 2,407,070Frame Sept. 3, 1946 2,408,064 Hall Sept. 24, 1946 FOREIGN PATENTS NumberCountry Date 613,000 Germany May 10, 1935 647,018 Germany June 25, 1937

